Analysis of Neutral B-Meson Decays into Two Muons

Physical Review Letters. 2022. Vol. 128. No. 4. Article 041801.

Aaij R., Abellán Beteta C., Ackernley T., Adeva B., Adinolfi M., Arzymatov K., Belavin V., Boldyrev A., Borisyak M., Derkach D., Hushchyn M., Karpov M., Maevskiy A., Popov S., Ratnikov F., Ryzhikov A., Ustyuzhanin A., Maevskiy D. S., Mokhnenko S.

Branching fraction and effective lifetime measurements of the rare decay B0s→μ+μ− and searches for the decays B0→μ+μ− and B0s→μ+μ−γare reported using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7 TeV, 8 TeV and 13 TeV, corresponding to a luminosity of 9 fb−1. The branching fraction Br(B0s→μ+μ−)=(3.09+0.46+0.15−0.43−0.11)×10−9 and the effective lifetime τ(B0s→μ+μ−)=(2.07±0.29±0.03) are measured, where the first uncertainty is statistical and the second systematic. No significant signal for B0→μ+μ− and B0s→μ+μ−γ decays is found and upper limits Br(B0→μ+μ−)<2.6×10−10 and Br(B0s→μ+μ−γ)<2.0×10−9 at the 95% CL are determined, where the latter is limited to the range mμμ>4.9GeV/c2. The results are in agreement with the Standard Model expectations.

Keywords: data analysis, particle physics, B physics, High Energy Physics - Experiment

Publication based on the results of: Machine learning to check and improve the quality of data collected at the Large Hadron Collider and other particle physics experiments (2022)